AI chips are hot. Here’s what they are, what they’re for and why investors see gold

The hottest thing in technology is an unprepossessing sliver of silicon closely related to the chips that power video game graphics. It’s an artificial intelligence chip, designed specifically to make building AI systems such as ChatGPT faster and cheaper.

Such chips have suddenly taken center stage in what some experts consider an AI revolution that could reshape the technology sector — and possibly the world along with it. Shares of Nvidia, the leading designer of AI chips, rocketed up almost 25% last Thursday after the company forecast a huge jump...